4" exhaust

[Firebirdedgar]

is it possible to fit a 4" tubing under my 2001 firebird. i know mufflex makes a 4" kit for the trans am. any one have a 4" exhaust?

[Yaba3800]

thats a bad idea. you would have absolutely no backpressure

[loser]

not many modifyed V8 guys run 4inch tubeing. 3inch is more than anough. even if you do go turbo or supercharger. you want some back-pressure, just not a alot.

[FireFighter]

Originally posted by Firebirdedgar:
is it possible to fit a 4" tubing under my 2001 firebird. i know mufflex makes a 4" kit for the trans am. any one have a 4" exhaust?

For WHAT?

We need a newbies forum.

[HAZ-Matt]

Please don't put 4" on.

[Big Bad James]

What do you need 4" piping for? Are you trying to scare the ricers away with the big chainsaw or what?

[Firebirdedgar]

just wanted to know your opinion about it. it is either this or 2.5" dual from header back.

[Yaba3800]

dont listen to the newbie comments. if we had a newbie forum how would any of them learn? 4" is too big for the engine size. 3 inch is plenty for it. and as far as v8's go. a single 4" system will outflow dual 3's and is used for very high performance or making noise/whichever you prefer

[articacid]

4 in is too much imho. theres not need for it ona v6. why would you go through the trouble of getting daul 2.5s when you can get a 3 in and have no probs.with 4 in you have the run a muffler if you want any back pressure, 3 in you dont have to.

a single 4" system will outflow dual 3's and is used for very high performance or making noise/whichever you prefer

a single 4 in will not out flow a true dual 3 in.

[Firebirdedgar]

thanks do yall know the diameter size of the header collector on a 2001 firebird.

[Fredless]

Originally posted by Firebirdedgar:
thanks do yall know the diameter size of the header collector on a 2001 firebird.

3 inches. Just get a 93-95 Single Cat LT1 catback for your car, like the hooker, edelbrock or magnaflow. I have a full 3" from my collector back, and its PLENTY overkill. If I remember correctly, 3" is enough for 330hp.

[articacid]

you cant forget the TSP rumbler or SLP loud mouth!

[Yaba3800]

a 4" single system will too outflow true dual 3's

['94firebirdv6]

Originally posted by loser:
not many modifyed V8 guys run 4inch tubeing. 3inch is more than anough. even if you do go turbo or supercharger. you want some back-pressure, just not a alot.

forced induction engines like as little backpressure as possible which is why alot of turbo guys run open down pipes. in my opinion 3" is bigger than necessary for a NA v6. for 99% of v6 fbodies a 2.5" is enough

[Muttled]

Originally posted by Yaba3800:
a 4" single system will too outflow true dual 3's

This is the second time I've used this formula in this forum ;)

4"^2*pi= ~50.25 square inches
2(3"^2*pi) = ~56.62 square inches

Therefore, the dual 3" is about 10% more free-flowing.

As to the question, a 4" exhaust will flow nearly twice as much as a 3" exhaust, and I doubt you need twice as much as what is generally considered the absolute max for our engine size [img]smile.gif[/img]